Dental materials journal最新文献

There is an increasing demand for bone graft procedures to create sufficient bone volume for implant fixture placement. Among various techniques, block bone grafting is considered a favorable option for both horizontal and vertical augmentation. To meet the required physical and biological characteristics, a novel hydroxyapatite (HA)-coated titanium dioxide (TiO₂) core block bone was developed in this study. The coating layer was designed with an HA concentration gradient to achieve superior compressive strength and wear resistance. The concentration gradient was confirmed by scanning electron microscopy/energy-dispersed X-ray spectroscopy, and coating stability was demonstrated through scratch testing. Furthermore, alizarin red S staining revealed that the HA gradient layer retained bone formation compared to a single-layer HA coating. Taken together, the developed doubled-layered HA gradient TiO₂ block bone shows strong potential as a substitute for conventional block bone grafts.

External apical root resorption (EARR) is a common complication of orthodontic treatment. Nevertheless, effective preventive strategies have not yet been established. Here, we demonstrated that administration of green tea catechin (epigallocatechin gallate: EGCG), at concentrations equivalent to habitual human daily intake when adjusted for rat body weight, prevented root resorption while preserving tooth movement in rats. An L-loop orthodontic appliance was used to induce vertical intrusive tooth movement for the maxillary first molar; EGCG was administered at doses of 1 and 2 mg every other day for 14 days (without EGCG for control). Tooth movement and root resorption were assessed using micro-computed tomography (µCT) as well as histological staining [hematoxylin and eosin (H-E) and tartrate-resistant acid phosphatase (TRAP)]. Despite no impairment in tooth movement in all groups, root resorption was significantly suppressed in the EGCG-administered groups. These findings suggest that habitual consumption of tea containing EGCG at daily concentrations may provide safe and effective strategies for orthodontic treatment.

Calcium phosphate granules can set when mixed with acidic phosphate solutions, forming an interconnected porous structure suitable for bone regeneration. However, the high acidity of these formulations may compromise their biocompatibility. This study investigates the feasibility of using less acidic phosphate solutions for α-tricalcium phosphate (α-TCP) granular cement to improve biocompatibility while ensuring sufficient setting. α-TCP granules were mixed with sodium phosphate solutions adjusted to pH 1, 2, 3, 5, and 7. Raising the solution pH prolonged the setting time while simultaneously reducing the hemolytic potential of the granular cement. Notably, no hemolysis was observed at pH≥3. All the granules set, forming interconnected porous structures and exhibiting partial conversion to calcium-deficient hydroxyapatite and octacalcium phosphate. These results demonstrate that using phosphate solutions with pH≥3 is an effective approach to optimize both the setting behavior and biocompatibility of α-TCP granular cement for clinical applications.

This study evaluated the effects of various surface pretreatments using chairside air abrasion with water injection or laboratory sandblasting devices on the shear bond strength of resin luting agents to three CAD-CAM prosthetic materials: resin composites, glass ceramics, and zirconia. Pretreatments included air abrasion with water injection (29 µm or 53 µm alumina or bioactive glass powder), conventional sandblasting with 50 µm alumina, and hydrofluoric acid etching for glass ceramics. Specimens were prepared after embedding the blocks. Surface roughness was measured after pretreatment, and shear bond strength was tested following cementation. Failure modes were analyzed using an optical profilometer. Results showed that air abrasion with 50 µm alumina, whether using a chairside device with water injection or a laboratory sandblasting device, produced comparable bond strength. These findings suggest that chairside air abrasion with 50 µm alumina is a clinically viable alternative to laboratory sandblasting for surface treatment of CAD-CAM prosthetic materials.

Surface pre-reacted glass ionomer (S-PRG) filler is a bioactive material capable of releasing multiple ions, including antibacterial borate ions. A self-adhesive resin composite containing S-PRG filler (Fit Sa; FS) has been reported to release high levels of borate ions. This study investigated the mechanical, bonding, and antibacterial properties of FS compared with other self-adhesive resin composites, conventional resin composites, and universal adhesive systems. The flexural strength of FS was comparable to that of conventional flowable composites and greater than that of several self-adhesive resin composites. The microtensile bond strength of FS was similar to that of a conventional self-etching adhesive system, whereas other self-adhesive resin composites showed lower strength or tended to fail prematurely. FS significantly inhibited Streptococcus mutans, while the other self-adhesive resin composites exhibited no antibacterial effect. These findings indicate that FS exhibits acceptable mechanical properties, bonding ability, and antibacterial potential, supporting its applicability for clinical use.

This study evaluated the effects of atmospheric nitrogen plasma on shear load resistance (SLR), penetration distance, and penetration area of adhesives used in the partial repair of bonded lingual retainers. Bonding gaps of 50, 100, and 150 μm were prepared between bovine enamel and composite resin, followed by plasma irradiation, and the surface free energy of the gaps was assessed. After adhesive application to the gap followed by curing the adhesive, the SLR, adhesive penetration distance, and penetration area of the treated surfaces were measured. In addition, these measurements were statistically compared with those of the untreated group. At 150 μm, plasma treatment significantly increased SLR, particularly with the 4-META/MMA-TBB resin adhesive. For all gap thicknesses, plasma treatment significantly enhanced the penetration distance and penetration area of the adhesives. These results suggest that plasma irradiation is an effective process for the partial repair of bonded retainers.

To assess the remineralization of artificial dentin lesions achieved with composites containing dicalcium phosphate dihydrate (DCPD) particles. Composites (42 vol% inorganic fraction) were tested: barium glass (BG; control), DCPD or 1DCPD:1BG. Degree of conversion (DC) was measured by FTIR. Ca²⁺ release was monitored using inductively coupled plasma optical emission spectrometry and scanning electrochemical microscopy (n=3). Artificial lesions were restored and kept in simulated body fluid for 28 days. Remineralization was assessed by mineral-to-matrix ratio (MMR; n=5) and nanoindentation (n=6). Data were analyzed using parametric tests (α=5%). DC ranged between 56.2 and 58.1% (p>0.05). Ca²⁺ release was 40.0±1.5 ppm and 18.4±1.6 ppm, respectively, for DCPD-only and DCPD+BG (p<0.001). Ca²⁺ release near the specimen surface reached 32 ppm within minutes after immersion. No differences in MMR were observed. Specimens in the DCPD-only group reached an elastic modulus higher than the control in the outer lesion (p<0.01). DCPD-containing composites may represent a promising approach to support dentin remineralization.

This study evaluated the effects of pre-polymerization temperature on the mechanical properties and viscosity of light-cure flowable composite resins for core build-up. Four materials (EverX Flow, BeautiCore LC Injectable, Filtek Fill and Core Flowable Restorative Plus, and iTFC Luminous Core LC Flow) were conditioned at 4, 23, or 60°C. Flexural strength, elastic modulus, fracture toughness, and viscosity were measured. Temperature significantly affected viscosity and, in BeautiCore, Filtek, and iTFC, also influenced flexural strength and fracture toughness. The short fiber-reinforced composite EverX Flow showed superior mechanical performance with consistent temperature stability, while BeautiCore and Filtek demonstrated improved flowability after pre-heating. iTFC exhibited a low modulus and minimal temperature sensitivity. These results indicate that temperature is a critical factor in the clinical performance of flowable composites, with pre-heating enhancing handling through viscosity reduction.

This study compared the biocompatibility and discoloration potential of Malaysian Portland cement (MPC), experimental MPC (EPC), radiopaque nano-zirconium oxide modified EPC (REPC), with ProRoot white mineral trioxide aggregate (WMTA) using human dental pulp stem cells (HDPSCs) with/without lipopolysaccharide (LPS). Cytotoxicity and cell attachment were evaluated using MTT assay and scanning electron microscope (SEM) after 24/72 h. For discoloration, the cements were placed in extracted human permanent maxillary incisors and color was measured spectrophotometrically. Results showed that all extracts except 100 mg/mL were non-cytotoxic. For LPS-treated groups (24 h), WMTA demonstrated higher cell viability than REPC (p<0.008). At 72 h, all groups were comparable. At 24 h, LPS-treated HDPSCs exhibited lower values than untreated HDPSCs (p<0.008). At 72 h, differences were comparable. SEM demonstrated favorable HDPSCs attachment. Tooth discoloration was the highest for WMTA, and lowest for REPC. In conclusion, the biological properties of REPC were comparable with WMTA. REPC did not cause tooth discoloration.

This review examines the development of denture marking from 1990 to 2025, driven by the growing need for identification in aging societies. Methods have evolved from direct techniques, such as ink and engraving, to indirect ones, including embedded quick response (QR) codes, radiofrequency identification (RFID) tags, and near-field communication (NFC) tags, which improve durability and data capacity. Materials now range from paper and photographs to metals and biocompatible laminates. Recorded information has advanced from basic personal details to encrypted digital data linked to medical records, raising concerns about privacy and ethics. The review emphasizes the need for cost-effective, standardized, and secure marking systems.